Method for rolling rails

Abstract

A method for rolling rails is provided wherein the final rolling operation includes processing of a rail blank in a leader pass universal mill stand and in a finishing pass universal mill stand. Both mill stands have horizontal rolls that form two roll passes, one of which is the leader roll pass and the other is a finishing roll pass. The rolls or the entire mill stands are interchanged from a previous location in a mill train to use an unused roll pass at the previous location, thereby doubling the roll life and eliminating the need to manipulate or otherwise handle the rail blank for passes in the mill stands.

I claim as my invention: 
     
       1. A method of hot-rolling elongated workpieces to form a rail or the like according to a schedule of roll passes in a rolling mill train which includes at least two rolling mill stands each having a pair of horizontal rolls and at least one vertical roll, said method including the steps of: providing each of said rolling mill stands with rolls defining two different roll-pass openings having preselected configurations to process a heated workpiece according to said schedule at only one of two different preselected locations in the rolling mill train, said vertical roll and a pair of horizontal rolls establishing one of the two different roll-pass openings in each rolling mill stand,   rolling heated workpieces in a designated one of the two roll-pass openings in each of the rolling mill stands,   replacing at least the horizontal rolls at one location with a pair of horizontal rolls after use at a different location to utilize an unused roll-pass opening at the previous location to process workpieces according to said schedule, and   rolling additional heated workpieces in said unused roll-pass opening.   
     
     
       2. The method according to claim 1 including the further steps of using a thrust bearing on the journal of each horizontal roll at the operator's side of the rolling mill train to transfer axially-directed roll forces to housings of said rolling mill stands, and coupling the horizontal rolls in the rolling mill train to a drive at the side of the mill train opposite said operator's side. 
     
     
       3. The method according to claim 1 or 2 wherein said two different roll-pass openings of each rolling mill stand comprises a leader roll-pass opening and a finishing roll-pass opening for producing rails. 
     
     
       4. The method according to claim 1 wherein said rolling mill stands include universal rolling mills. 
     
     
       5. The method according to claim 1 including the further steps of providing at least three of the said rolling mill stands each having two different roll-pass openings to process workpieces at one of two different locations, and storing one of said three rolling mill stands, said step of replacing at least the horizontal rolls being further defined to include replacing a rolling mill stand at one location with the stored rolling mill stand. 
     
     
       6. A method of hot-rolling elongated workpieces to form a rail according to a schedule of roll passes in a rolling mill train which includes at least two universal rolling mill stands, a pair of horizontal rolls and at least one vertical roll, said method including the steps of: hot-rolling a workpiece to a desired configuration for final rolling in at least two universal finishing mills according to said schedule,   providing each of said universal rolling mill stands with two different roll-pass openings having preselected configurations to process a heated workpiece according to said schedule at only one of two different preselected locations downstream in the mill train from the said step of hot-rolling a workpiece to a desired configuration,   rolling heated workpieces in a designated one of the two roll-pass openings in each of the universal rolling mill stands,   replacing at least the horizontal rolls in a universal rolling mill stand after use at a different location to utilize an unused roll-pass opening at the previous location to process workpieces according to said schedule, and   rolling additional heated workpieces in said unused roll-pass opening.   
     
     
       7. The method according to claim 6 including the further step of using an edger mill to process a workpiece at the discharge side of one of said two universal rolling mill stands, and thereafter processing the workpiece in the second of said two universal rolling mill stands in the rolling mill train.   
     
     
       8. The method according to claim 6 or 7 wherein said two different roll-pass openings of each universal rolling mill stand comprise a leader roll-pass opening and a finishing roll-pass opening. 
     
     
       9. The method according to claim 6 wherein said step of replacing at least the horizontal rolls includes replacing a universal rolling mill stand at one location with a universal rolling mill stand after use at a different location to process workpieces according to said schedule. 
     
     
       10. The method according to claim 6 wherein said two different roll-pass openings of each universal rolling mill stand comprises a leader roll pass and a finishing roll pass, and wherein said step of rolling additional heated workpieces includes using a vertical roll of a universal mill to contact the top of a rail workpiece in said leader pass and using a vertical roll of a universal mill to contact the bottom of a rail workpiece in said finishing pass.